作者:Alistair J. M. Farley、Christopher Sandford、Darren J. Dixon
DOI:10.1021/jacs.5b10226
日期:2015.12.30
The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated α-substituted acrylate esters catalyzed by a bifunctional iminophosphorane organocatalyst under mild conditions is described. The strong Brønsted basicity of the iminophosphorane moiety of the catalyst provides the necessary activation of the alkyl thiol pro-nucleophile, while the two tert-leucine residues flanking a
The present invention provides a bifunctional catalyst of the formula (1): wherein: each R
1
is independently selected from an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted aralkyl group and an optionally substituted alkaryl group; Z represents a divalent organic linking moiety optionally containing one or more stereocentres; and EWG represents an electron-withdrawing group.
(R
1
)
3
P═N—Z—NH-EWG (1)
Bifunctional Iminophosphorane‐Catalyzed Enantioselective Nitroalkane Addition to Unactivated α,β‐Unsaturated Esters
作者:Daniel Rozsar、Alistair J. M. Farley、Iain McLauchlan、Benjamin D. A. Shennan、Ken Yamazaki、Darren James Dixon
DOI:10.1002/anie.202303391
日期:——
The first intermolecular enantioselectiveaddition of nitroalkanes to unactivated α,β-unsaturated esters is described, catalyzed by a bifunctional iminophosphorane (BIMP) superbase. This fundamental synthetically relevant transformation proceeds with high enantiomeric excesses and yields over a wide range of feedstock substrates, providing pharmaceutically relevant building blocks in a single step
Bifunctional Iminophosphorane Catalyzed Amide Enolization for Enantioselective Cyclohexadienone Desymmetrization
作者:Charmaine Y. X. Poh、Daniel Rozsar、Jinchao Yang、Kirsten E. Christensen、Darren J. Dixon
DOI:10.1002/anie.202315401
日期:2024.1.25
The enolization of 2-arylacetamides, followed by an enantioselective intramolecular conjugate addition to tethered 2,5-cyclohexadienones, yielding saturated fused N-heterocycles, is described. The transformation is achieved by employing a bifunctional iminophosphorane (BIMP) superbase catalyst and represents the first unactivated carboxamide deprotonation in a metal-free, catalytic, and enantioselective